As everybody knows, the new-born infant has no consciousness. Preyer has shown that it is only developed after the child has begun to speak; for a long time it speaks of itself in the third person. In the important moment when it first pronounces the word “I,” when the feeling of self becomes clear, we have the beginning of self-consciousness, and of the antithesis to the non-ego. The rapid and solid progress in knowledge which the child makes in its first ten years, under the care of parents and teachers, and the slower progress of the second decade, until it reaches complete maturity of mind, are intimately connected with a great advancement in the growth and development of consciousness and of its organ, the brain. But even when the pupil has got his “certificate of maturity” his consciousness is still far from mature; it is then that his “world-consciousness” first begins to develop, in his manifold relations with the outer world. Then, in the third decade, we have the full maturity of rational thought and consciousness, which, in cases of normal development, yield their ripe fruits during the next three decades. The slow, gradual degeneration of the higher mental powers, which characterizes senility, usually sets in at the commencement of the seventh decade—sometimes earlier, sometimes later. Memory, receptiveness, and interest in particular objects gradually decay; though productivity, mature consciousness, and philosophic interest in general truths often remain for many years longer.
The individual development of consciousness in earlier youth proves the universal validity of the biogenetic law; and, indeed, it is still recognizable in many ways during the later years. In any case, the ontogenesis of consciousness makes it perfectly clear that it is not an “immaterial entity,” but a physiological function of the brain, and that it is, consequently, no exception to the general law of substance.
From the fact that consciousness, like all other psychic functions, is dependent on the normal development of certain organs, and that it gradually unfolds in the child in proportion to the development of those organs, we may already conclude that it has arisen in the animal kingdom by a gradual historical development. Still, however certain we are of the fact of this natural evolution of consciousness, we are, unfortunately, not yet in a position to enter more deeply into the question and construct special hypotheses in elucidation of it. Palæontology, it is true, gives us a few facts which are not without significance. For instance, the quantitative and qualitative development of the brain of the placental mammals during the Tertiary period is very remarkable. The cavity of many of the fossil skulls of the period has been carefully examined, and has given us a good deal of reliable information as to the size, and, to some extent, as to the structure, of the brain they enclosed. We find, within the limits of one and the same group (the ungulates, the rodents, or the primates), a marked advance in the later miocene and pliocene specimens as compared with the earlier eocene and oligocene representatives of the same stem; in the former the brain (in proportion to the size of the organism) is six to eight times as large as in the latter.
Moreover, that highest stage of consciousness, which is reached by man alone, has been evolved step by step—even by the very progress of civilization—from a lower condition, as we find illustrated to-day in the case of uncivilized races. That is easily proved by a comparison of their languages, which is closely connected with the comparison of their ideas. The higher the conceptual faculty advances in thoughtful civilized man, the more qualified he is to detect common features amid a multitude of details, and embody them in general concepts, and so much the clearer and deeper does his consciousness become.
[CHAPTER XI]
THE IMMORTALITY OF THE SOUL
The Citadel of Superstition—Athanatism and Thanatism—Individual Character of Death—Immortality of the Unicellular Organisms (Protists)—Cosmic and Personal Immortality—Primary Thanatism (of Uncivilized Peoples)—Secondary Thanatism (of Ancient and Recent Philosophers)—Athanatism and Religion—Origin of the Belief in Immortality—Christian Athanatism—Eternal Life—The Day of Judgment—Metaphysical Athanatism—Substance of the Soul—Ether Souls and Air Souls; Fluid Souls and Solid Souls—Immortality of the Animal Soul—Arguments for and Against Athanatism—Athanatist Illusions
When we turn from the genetic study of the soul to the great question of its immortality, we come to that highest point of superstition which is regarded as the impregnable citadel of all mystical and dualistic notions. For in this crucial question, more than in any other problem, philosophic thought is complicated by the selfish interest of the human personality, who is determined to have a guarantee of his existence beyond the grave at any price. This “higher necessity of feeling” is so powerful that it sweeps aside all the logical arguments of critical reason. Consciously or unconsciously, most men are influenced in all their general views, and, therefore, in their theory of life, by the dogma of personal immortality; and to this theoretical error must be added practical consequences of the most far-reaching character. It is our task, therefore, to submit every aspect of this important dogma to a critical examination, and to prove its untenability in the light of the empirical data of modern biology.
In order to have a short and convenient expression for the two opposed opinions on the question, we shall call the belief in man’s personal immortality “athanatism” (from athanes or athanatos == immortal). On the other hand, we give the name of “thanatism” (from thanatos == death) to the opinion which holds that at a man’s death not only all the other physiological functions are arrested, but his “soul” also disappears—that is, that sum of cerebral functions which psychic dualism regards as a peculiar entity, independent of the other vital processes in the living body.